Interesting Findings on the Dyno - OpenFlash/Vishnu tuned

[ck-GT86]

Originally Posted by cjd

The beta thread actually had some discussion on the topic that may be relevant, but I'm not sure that wasn't resolved. I know I've occasionally had issues I might expect to dyno like this, but I'm still on the beta version (still trying to get my computer working after a trashed partition table and don't drive much at all...)

It's definitely inconsistent, but may be load related.

I too are running the beta maps, haven't updated to any of the recent ones yet.

For what it's worth, I received my GrimmSpeed intake yesterday; I'm not holding off on installing it, it's too badass to keep in it's box. A dyno after this point is going to have skewed numbers when compared to the MaHa session -- as expected since the engine will be setup differently.

I've texted Shiv to let him know what my plans are -- fingers aren't going to be pointed anywhere right now. To make fair, I'm going to schedule a dyno session (maybe two) with other operators around the area. If it so happens that those dynos also reproduce a dip, then we'll circle back.

Moving on, if anyone experiences a dip from their OFT tune, please share it. It'd be beneficial if we could compare car specs/mods to try and narrow down an issue, be that: tune, mechanical, or anything else related.

.ck

[steve99]

Originally Posted by ck-GT86

I too are running the beta maps, haven't updated to any of the recent ones yet.

For what it's worth, I received my GrimmSpeed intake yesterday; I'm not holding off on installing it, it's too badass to keep in it's box. A dyno after this point is going to have skewed numbers when compared to the MaHa session -- as expected since the engine will be setup differently.

I've texted Shiv to let him know what my plans are -- fingers aren't going to be pointed anywhere right now. To make fair, I'm going to schedule a dyno session (maybe two) with other operators around the area. If it so happens that those dynos also reproduce a dip, then we'll circle back.

Moving on, if anyone experiences a dip from their OFT tune, please share it. It'd be beneficial if we could compare car specs/mods to try and narrow down an issue, be that: tune, mechanical, or anything else related.

.ck

you should log your tune

check your fuel trims ltft high trims can cause bogging/hesitation
log knock bad fuel can cause iam drop due knock in 1500-3500 area reducing power.

if you go back to dyno log the run with oft or other logging device.

[cjd]

I'd move to the release tunes too (rather, work from the latest available, always the best place to start troubleshooting)

I'll be doing that before installing my GS intake.

[skidmark86]

Originally Posted by Nivek

I know some members suggested that the alleged dip should be noticeable yet members are not feeling it when accelerating.

For those who have the tune in question, please try this to simulate the MAHA dyno.

Scenario 1:
Find a long stretch of road that is uphill, the steeper the better, and put in 5th gear and accelerate from 2,500rpm with your foot to the floor -- w/traction control off (so nobody can mistakenly blame that for any unexpected results).

What is your experience?

Scenario 2:
Find a long stretch of open highway, put it in 5th gear at 1,800 rpm and accelerate to 65 (if you can even get the engine to produce power).

What is your experience?

Disclaimer: I am a BRZ owner and am part of the moderator team of an STI specific forum. I read this forum and don't post much but I'd like to see whether your findings are consistent with my belief about why it might be uncommon to *feel* the reported dip that appears on the MAHA dyno printout.

The above scenarios should simulate the type of load conditions generated by the MAHA dyno and by reproducing the load condition this should help you determine whether you got dip.

I'm confused why we are debating this now. The point is that nobody seems to feel this during normal daily or track driving. Why should we purposely put the car into a precarious driving situation to attempt to simulate the "almighty" MAHA dyno? The torque dip doesn't really matter when I'm trying to accelerate uphill in 5th??? I'm not sure why this is relevant.

Who says, "Damn, I wish there wasn't a huge torque dip when I'm trying to redline this huge hill?!?!?!"

[Nivek]

The dyno was likely conducted in either 5th or 6th gear. The above test is only relevant if someone is trying to determine whether they can feel the dip. Any testing by members in gears other than those would not necessarily provide the proper comparison.

[skidmark86]

Originally Posted by Nivek

The dyno was likely conducted in either 5th or 6th gear. The above test is only relevant if someone is trying to determine whether they can feel the dip. Any testing by members in gears other than those would not necessarily provide the proper comparison.

I can see where you are going with this in the scientific sense, but for 99.9% of drivers, this is going to be irrelevent to their driving habits. It may or may not exist, but in the scheme of things this seems to be isolated to very rare driving situations.

[Nivek]

I am simply providing the method to properly assess whether someone can feel the dip seen on the MAHA dyno. If this was on a six speed STI, the dyno test would normally take place in 4th gear.

I am not a tuner but whatever gear was used for the MAHA test should be used when you drive your car. Someone should call and verify with Mann Engineering or the OP what gear was used.

As to whether a dip like this should be concerning, that is for the tuners to chime in on! If I encountered a dip like this on my car, I would contact multiple tuners and find out whether my car has been tuned right.

[skidmark86]

Originally Posted by Nivek

I am simply providing the method to properly assess whether someone can feel the dip seen on the MAHA dyno. If this was on a six speed STI, the dyno test would normally take place in 4th gear.

I am not a tuner but whatever gear was used for the MAHA test should be used when you drive your car. Someone should call and verify with Mann Engineering or the OP what gear was used.

As to whether a dip like this should be concerning, that is for the tuners to chime in on! If I encountered a dip like this on my car, I would contact multiple tuners and find out whether my car has been tuned right.

I guess my only point on this is that people have data logged these tunes and have only seen good results. I just don't regard this as an "unsafe" tune.

I do appreciate that you are not being a normal NASIOC asshole about this.

[ck-GT86]

Originally Posted by Nivek

I am simply providing the method to properly assess whether someone can feel the dip seen on the MAHA dyno. If this was on a six speed STI, the dyno test would normally take place in 4th gear.

I am not a tuner but whatever gear was used for the MAHA test should be used when you drive your car. Someone should call and verify with Mann Engineering or the OP what gear was used.

As to whether a dip like this should be concerning, that is for the tuners to chime in on! If I encountered a dip like this on my car, I would contact multiple tuners and find out whether my car has been tuned right.

The dyno was done in 5th gear, from what I was told.

.ck

[Nivek]

I called this morning and was told it was not 5th or 6th but 4th gear. If we could get a copy of the full uncropped dyno graph, it should say. Assuming it was 4th, then the tests I proposed should be done in that gear.

[Lav]

Originally Posted by Shiv@Openflash

Group hug needed

This thread and how you deal with slander convinced me to get an OFT. You have so much confidence in your work. Cant wait till it arrives. Keep up the good work

bibbity boppity give me the zoppity